What I learnt about food safety week commencing 29th April

FAcebook logopngChapter Four of error nomics provided some fascinating insight on how our memory’s work, and how we reconstruct memories of past events to put ourselves in a favourable light. This is not the same as conscious lying, it is more like a sub conscious bending of the truth which, as far as we are concerned IS the truth.

In terms of food safety, I found less obvious parallels in this chapter, but a couple of ideas sprang to mind:

1.   If we reconstruct the past to present our actions favourably it is harder to learn from our mistakes.

2.   It is another good reason why any accident or food poisoning investigation should be completed promptly. And it may be harder to uncover the truth at all.

3.   It may affect our relationship with colleagues; particularly if things went wrong in the past. After a few years the memory of our own actions will be become more positive which means our opinion of others may diminish.

4.   It increases the likelihood of us blaming others, sometimes unfairly.





These are the examples presented in the book:

In one experiment at an American college, students were asked to recall their high school grades from a few years earlier 29% recalled it incorrectly with most mistakes (79%) being an upgrade on actual performance.

Students recall accuracy for A’s (89%) was also higher than D’s (29%).

As I write this, I’m casting my mind back to job appraisals I’ve had over the years and it’s true I can recall positive feedback far more easily that any ‘areas for improvement’.



The chapter goes on to explain how this perception can extend to how we literally see ourselves. In an experiment volunteers recognised their own faces in a crowd far more quickly when their image was computer enhanced to be more attractive. What’s more they were more likely to identify the enhanced image as ‘the real me’ when compared to non-enhanced portraits.

Hindsight Bias.

The book makes an important point about the word bias. It does not mean an overtly prejudiced point of view, but rather a “a small nude to our judgement that occurs without being aware of it”.

Hindsight bias is how we reconstruct past events, including our own thoughts and feelings once we know the outcome.

Last weeks Blog examined how people rarely change their mind and when they do, according to Nobel Laureate Daniel Kahneman people “reconstruct their past opinion - they believe they always thought that”.

In terms of food safety and health and safety I’ve known several occasions where individuals and companies have been criticised following an accident; in retrospect it was ‘obvious’ the accident was ‘inevitable’.




As an auditor I’ve given a few low scores over the years and in many cases the manager will blame a chef with a comment such as “I told him the kitchen was dirty!”

Perhaps the manager did, but how often and how forcefully? Did the manager state the urgency and ensure something was done about it? Or was it just a passing comment amongst hundreds of conversations that took place and that only now, in hindsight does the manager remember it as a significant point?

The same may also hold for the Area Manager who warned the site manager he/she needed to be more assertive.

Hindsight bias coupled with a strong tendency to see ourselves in a positive light may result in unfair attribution of blame and makes it harder to learn from mistakes.

Examples of hindsight bias given in erro nomics include historians who focus on specific past events to demonstrate, for example the attack on Pearl Harbour was inevitable. The historian’s arguments are persuasive; however, they have been achieved only by supressing some facts at the expense of others – a process called creeping determinism.

See the chef, area manager and accident investigations noted above.



In another study gamblers were asked to note their thoughts after the bet was complete. When winning, they focused on how right they were, how inevitable the outcome would be with comments such as “I just knew it”. However, then losing they tended to blame something completely out of their control or a fluke event “I WOULD have won if he hadn’t missed that open goal” etc.

As with all biases (small nudges to our decision making) most of us will have great difficulty acknowledging them and in fact most will deny them. And this can pose dangers.

Say, I’m completing an alleged food poisoning investigation where initial reports suggest chicken was to blame. Now let’s imagine I had conducted an audit at the site a few months earlier and noted the chefs rarely checked the temperature of cooked food and when they did, the probe was not sanitised.



It’s easy for hindsight bias to kick in. It was obvious these poor practices would lead to food poisoning and I’m a pretty good auditor for picking this up. It’s just a shame the site didn’t listen to my advice…… now look what’s happened.

I question the chefs and they don’t even know what the cooking temperature is! I look at their records and I see there are regular gaps in the ‘cooking’ temperature box.

All of this will fail to identify the real cause of the illness; a child sitting on the same table prior to the affected party had been sick.

Fortunately, during audits and investigations we have a series of checks and balances to reduce the likelihood of such mistakes. Unfortunately for the most part of our lives, we don’t.





Last week I instigated a discussion on the use of bleach in kitchens and as I mentioned at the time there were many related comments regarding the practice of soaking sponges.

This week a group member poster the following advice which I think sums up concerns over ‘soaking’.

“I absolutely agree that soaking sponges is not great practice due to chlorine’s ability to become ineffective when it is bound up with chloramines and the fact that bacteria love moisture. Increasing the Aw in any situation is scary. While on occasions I have come across some premises using sponges to clean, those that do have either a single use procedure or they are used and dried before reuse. It is important to note that these are used to clean and not in the sanitisation process”.

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